Device for instruction in reading and calculating



(No Model.)

W. W. HALLETT. DEVICE FOR INSTRUCTION IN READING AND CALCULATING.

No. 481,728. PatentedAug. 30-, 1892.

Minesses:

UNTTED STATES PATENT OFF CE.

\VILLIAM IV. I'IALLETT, OF LEE, ILLINOIS.

DEVICE FOR INSTRUCTION IN READING AND CALCULATING.

SPECIFICATION forming part of Letters Patent No. 481 ,728, dated August30, 1892.

Application filed February 17, 1892. Serial No. 421,890. (No model.)

.T at whom it may concern:

Be it known that I, WILLIAM IV. IIALLETT, a citizen of the UnitedStates, residing at Lee, county of Lee, and State of Illinois, haveinvented certain new and useful Improvements 1n aDevice for Instructionin Reading and Calculating, of which the following isaspecification.

The improvements herein shown applyparticularly to that class ofmachines illustrated and described in Letters Patent of the UnitedStates numbered 462,405 granted to me November 3, 1891, wherein tworevolving disks bearing educational matter are screened from Viewexcepting such portions as coincide with openings in the obscuringcurtain and with which on the curtain may be written other matter to beread in conjunction with the words or signs on the disks.

In the accompanying drawings, Figure 1 is an isometrical representationof my device for reading and calculating as seen from the rear. Fig. 2is an isometrical representation of the same, looking at its face side.Fig. 3 is asectional View of the parts necessary to withdraw theintermediate gear from between the two larger gears and for looking itin or out of engagement therewith. Fig. 4 is an isometricalrepresentation of one of the slips which slide in the grooves in theface of the screen.

In the construction of my calculator I first provide a base-piece 1,secured-to and arising from which are the two sides 2 of thesupporting-frame, joined together by the connectingrods 3, which holdthe sides in fixed relation. In the upper outer ends of thesupportingframe I journal the two shafts 4 and 5, each bearing upon itsforward end a disk, upon which is placed educational matter, the shaft 4carrying the disk 6 and the shaft the disk 7, the latter disk partiallyoverlying the former. These disks are secured rigidly to theirrespective shafts by thumb-nuts, and on the rear ends of the shafts andrigidly secured thereto are the two gears 9 and 10 on shafts 4 and 5,respectively, and outside the gear 9 I secure the hand-crank 11, bywhich the shafts are rotated. To communicate motion from the drive-shaft4 to the shaft 5 I interpose a gear-wheel 12 between those 9 and 10. Thegear 12 is j ournaled loosely in a verticallysliding bracket 13, and avertically-elongated opening14inthebracketadmitsathumb-screw 15, havinga screw-threaded connection with thesu p porti n g-f ram e, allowing thewithdrawal of the intermediate gear from engagement with the other two.A coil-spring 16 extends between the bracket and one of theconnecting-rods 3 of the frame, tending to hold the gear 12 inengagement with the gears 9 and 10, though it may be locked out ofengagement by means of the thumb-screw 15.

To prevent a turning of the disks in other than one direction, I providea flexible bar 18, pivoted in the frame midway between the shafts on oneof the connecting-rods 3 and extending over the stud 10. This barengages the teeth of the serrated wheel 20. Both shafts bearratchet-wheels, the teeth of which are set in opposite directions, thatthe flexible bar 18 may be turned to engage either ratchet.

On lines radiating from the centers of the disks 6 and 7 I'form words,signs, letters, pictures, or other educational matter to be presented tothe learner.

In constructing sentences I may provide one disk with nouns and theother with verbs.

On the base 1, before the disks, I secure angle-bracket 21, the bars ofwhich are mov able secured to the base 1 by the threaded rods 22,passing through elongated openings 23 in the bracket 21. One leaf of thespringhinge 24 is affixed to the base of the bracket 21 and to its freeleaf is secured the plate 25, to which I attach the hand-knob 26.

To cover the face of the disks, I provide a screen 27, of some stiffmaterial, held upright in the bracket 21, and this screen has openings28, by which certain portions of the surface of the disks are exposed toview. This screen is formed in two sections, joined together by hinges,and on its face bears strips 29, about on a level with the upper andlower edges of the openings 28, provided with grooves in their adjacentedges.

To slip into the grooves I provide detached pieces 31 of card-board orother suitable material, bearing letters, signs, words,punctuation-marks, &c., to be used in conjunction with the matterexposed and to be arranged in suitable order in reference to the matteron the disks. Other slips 32 are made in blank to partially close theopenings of the screen and thus hide certain portions of the exposedsurface of the disks.

In use when arithmetic is to be taught with my calculator I place thedisks bearing numbers on the shafts and secure the screen in place,covering those numbers not to be considered and placing the slip 31,bearing the proper sign, on the screen between the openlngs.

The jointing of the screen is to allow its folding into a moreconvenient shape in packing for transportation.

I claim as my invention

